Morphology

As is true in many spider species, females of this species grow to much larger size than males. Adult female body length ranges from 19 to 28 mm (3/4 to 1 1/8 in.), while males reach only 5 to 9 mm (1/4 - 3/8 in.). In both sexes, the shiny, egg-shaped abdomen has striking yellow or orange markings on a black background. The forward part of the body, the cephalothorax, is covered with short, silvery hairs. Legs are mostly black, with red or yellow portions near the body.

Like other orb-weavers (family Araneidae), this species has three claws per foot, one more than most spiders. Orb-weavers use this third claw to help handle the threads while spinning. Also in common with other orb-weaving spiders (and most, but not all spiders generally), A. aurantia has a venomous bite that immobilizes prey that is caught in its web.